Catheter infections are one of the biggest problems in health care today. An improved method for treating catheter infections would be useful to the medical community. Catheter infections often lead to catheter-related bloodstream infections (CRBSI's). This is a dreaded complication with an attributable mortality of 12-25% for each infection. The annual incidence of catheter related bloodstream infections is estimated to be 250,000 events per year in the US, leading to approximately 28,000 deaths per year. The median rate of catheter-related bloodstream infections in ICUs ranges between 1.8 to 5.2 per 1000 catheter days, with average costs between $23,508 and $56,000 according to some estimates. The annual cost of caring for patients with central venous catheter related bloodstream infections ranges from $296 million to $2.3 billion.
Catheter infections are associated with bacteria that form a polysaccharide matrix called a biofilm. Bacteria can colonize the external surface of a catheter or can colonize the internal lumen of a catheter. For short-term catheters, infections are primarily extraluminal. Long-term catheters are primarily associated with intraluminal bacterial colonization. The biofilm on the internal lumen has been shown as the primary infection source in short-term central venous catheters (CVCs) as early as 4 to 6 days after insertion. With catheters indwelling longer than 10 days, intraluminal biofilm is almost always associated. In intraluminal catheter infections, biofilm may establish itself along the entire length of the catheter, as well as at the catheter opening.
Additionally, catheter-associated urinary tract infections (CAUTI's) are also a large problem within the medical system. An estimated 15-25% of hospitalized patients receive urinary catheters, and if a urinary tract infection (UTI) is diagnosed in a hospitalized patient, 75% of the time it is associated with a urinary catheter. These infections are among the most common type of health-care associated infection, result in increased hospital stays, and cost the healthcare system $400 to $500 million per year. UTI's are associated with more than 13,000 deaths per year. Like central catheters, urinary catheters can harbor bacterial colonies that can produce a luminal biofilm that may be resistant to conventional antibiotics.
Currently, there is no established, effective method for treating catheter infections. The currently available methods of treating CRBSI's and CAUTI's typically comprise removing the infected catheter, introducing a new catheter into the patient, and treating the patient with a course of antibiotics. These methods are problematic because of increasing antibiotic resistance, especially in the hospital environment; patient discomfort associated with removing and replacing catheters; possible disfiguration associated with catheter insertion; expense associated with the additional medical care; costs associated with replacing catheters with suspected infections; and increased risk venous stenosis and thrombosis.
Ultraviolet (UV) light is a non-molecular based antimicrobial agent that has been investigated for catheter infection treatment. UV light has a particular band of wavelengths, 250-280 nm (UVC band), that is considered germicidal. The germicidal action occurs by the production of thymine dimers in microbial DNA. The use of UV light for disinfection is well established in water treatment. Although biofilm may attenuate microbial response to UV light, UVC light can induce DNA damage in microbes through a biofilm matrix. However, attempts to date to treat (or prevent) catheter infections using UV light have not solved the problem.
As described above, there exists a need for new technologies to both treat and prevent intraluminal catheter infections. The disclosed UV light-based sterilization systems, devices, and methods are generally directed toward addressing one or more of the problems set forth above.